Support for conductors



zmlgms 393% J. J. TAYLOR SUPPORT FOR CONDUCTORS Filed Feb. 8, 1954 INVENTOR m M mm fim mm 04 d Patented Feb. 18, 1936 {TED STATES SUPPORT FOR CONDUCTORS John J. Taylor, Barberton, Ohio, assignor to The Ohio Brass Company, Mansfield, Ohio, a corporation of New Jersey Application February 8, 1934, Serial No. 710,258

6 Claims.

This invention relates to suspension clamps for holding electrical conductors, and has for one of its objects to provide a clamp which will reduce the liability to breakage due to fatigue of the conductor strands.

Another object of the invention is to provide a clamp which will produce a minimum amount of bending of the supported conductor caused "by vibration.

A further object of the invention is to provide a clamp in which the radial stress on the conductor produced by the clamping action will be distributed along the conductor and will not be coincident with the stresses produced by vibration.

A further object of the invention is to provide a pivotally supported clamp in which the pivotal axis will be substantially at the point of intersection of the tangent lines of the: conductor where it leaves the clamp.

Other objects and advantages will appear from the following description.

The invention is exemplified by the combination and arrangement of parts shown in the accompanying drawing and described in the following specification, and it is more particularly pointed out in the appended claims.

In the drawing:

Fig. l is a fragmentary elevation with parts in section showing one embodiment of the present invention.

Fig. 2 is a top plan view of the supporting saddle shown in Fig. 1.

Fig. 3 is an end elevation in part section on line 33 of Fig. 1.

There are a number of stresses to which an electrical conductor are submitted which tend to produce fatigue in the conductor strands and in time cause breakage of the conductor. A conductor is carried by supporting towers or other structures at spaced points along the right-ofway and hangs in catenary formation between the points of support. The conductor strands are therefore subject to a tension produced by the weight of the conductor or the normal tension of the catenary. The conductor may also be subject to bending and compressive stresses resulting from the angle of sag or take-oil at the point of support. The conductor may also be subject to radial pressure due to a clamping action. It is also subject to stresses produced by vibration of the conductor. It is obvious that decreasing one or all of these stresses or staggering them so that they do not coincide will increase the fatigue life of the conductor.

The normal tension of the catenary may be decreased "by increasing the sag of the conductor between points of support, but this requires higher towers for a given ground clearance and increases lightning hazard and first cost of the line. The bending and compressive stresses resulting from the angle of sag at the clamp may be decreased by employing a clamp designed to obtain a large radius of curvature of take-oil". Excessive radial pressure produced by clamping 10 action may be avoided by carefully determining the clamping action required and designing the clamp so as not to exceed the amount of pressure necessary. 'The stress at any point, due to clamping action, may be decreased by distrib- 15 uting the clamping effort over a suflicient area to develop the required slip load without undue radial pressure at any point. The effect of radial pressure may be offset by tapering the radial compressive stress so that it decreases toward the extremity of the clamping piece. The effect of vibration may be reduced by reducing the amplitude of vibration in the conductor, as by vibration dampers, or by reducing the bending effeet resulting from accepted amplitude or combining both of these 'expedients. The present invention comprises a clamp designed to take advantage of the various factors which may be employed for reducing the danger of fatigue to which the conductor is subjected.

In the drawing the numeral lll designates a saddle or supporting member having a seat H for receiving a conductor. The seat is curved in cross section, as shown in Fig. 3, to conform to the curvature of the conductor. A keeper piece '12 engages the upper face of the conductor and is provided with downwardly extending sides I3 which give alarge area of contact for a considerable distance along the central portion of the keeper piece. The sides 13 are tapered oil at each end of "the keeper piece, as indicated at I'd, and the keeper piece is made oi material having suflici-ent elasticity so that the tapered portions M will result in a graded pressure on the cable, gradually decreasing towards the ends of the keeper piece. The keeper piece I2 is held in place by 'U -bol-ts I!) which are placed close to the middle of the keeper piece and are flattened to distribute the pressure over a considerable porr tion of the keeper. The U-bolts are arranged close together near the middle of the clamp to permit tapering the ends of the keeper without unduly extending its length. By this arrangement all of the radial compression for clamping the conductor is applied to the conductor near the middle of the supporting saddle l0 and at a portion of the conductor not subject to bending, due to vibration or due to the angle of take-off.

It will be noted from Figs. 2 and 3 that the sides of the saddle l0 are offset outwardly at the middle of the clamp to provide pockets for the U-bolts l5 and for the suspension member IS. The pivot bolt I1 connects the ears IS on the sides of the saddle with the suspension member IS, the bolt being placed closely adjacent the upper surface of the keeper piece I2 and having the pivotal axis of suspension of the clamp at the point of intersection of lines tangent to the conductor where it leaves the seat I I at the ends of the saddle [2. Since the conductor is supported in a catenary curve, it will of course have an angle of take-oil inclined downwardly at the end of the seat II so that the axis of rotation of the clamp upon the pivot pin I! will be above the axis of the conductor at the middle of the clamp. The distance above the center of the conductor would depend upon the tension in the clamp, and the clamp should be designed so that the. pivotal axis will be correctly located for the tension to which the cable supported by the conductor is to be subjected. If the allowable angle of sag is assumed, it will then of course be an easy matter to determine the correct position for the pivotal center for the clamp. If a permissible tension in the cable is assumed, then it will be possible to compute the angle of sag from the length of the span and the weight of the conductor and the position of the pivotal support can be determined accordingly.

I claim:

1. A conductor support comprising an elongated saddle member having a conductor seat therein, a keeper piece for holding the conductor in said seat and means for clamping said keeper piece against said conductor, the end portions of said keeper piece beyond said clamping means having the longitudinal elements of the contact faces thereof substantially parallel with the longitudinal elements of said seat so that said end portions will engage a conductor on said seat, said end portions being tapered to grade the pressure exerted thereby on the conductor.

2. A conductor support comprising an elongated saddle member having a conductor seat therein, a keeper piece for retaining a conductor in said seat and means for clamping said keeper piece against said conductor, said keeper piece being formed of resilient material and having an extended portion at each end thereof bent to follow the longitudinal contour of a conductor on said seat and sufilciently tapered to produce a material grading in the pressure exerted by said keeper piece upon the conductor.

3. A conductor support comprising an elongated saddle member having a seat therein for supporting a conductor, a keeper for retaining a conductor in said seat and clamping bolts for holding said keeper piece against said conductor, said bolts being disposed close together near the middle of said keeper piece and having extended flat portions engaging the surface of said keeper piece to distribute the clamping force for an extended distance along said keeper piece, said keeper piece beyond said bolts being curved downwardly and gradually tapered towards the ends thereof to produce a grading of the force exerted on the conductor by the portions of the keeper piece extending beyond said bolts.

4. A support for a conductor comprising an elongated channel shaped saddle member having a seat therein for receiving a conductor, the sides of said saddle member being offset outwardly at the middle of said member to provide pockets at the sides of the conductor in said seat, a keeper piece engaging said conductor adjacent said pockets and having side flanges forming a contact face extending about the upper portion of said conductor, U-bolts having flattened portions engaging said keeper piece adjacent said side flanges and having extended contact along the surface of said keeper piece to distribute the clamping effort of said U-bolts relative to the conductor, the end portions of said keeper piece being shaped to follow the longitudinal contour of the conductor beyond said U-bolts the side flanges of said keeper piece beingtapered toward the ends of said keeper beyond the U-bolts for a sufficient distance to effect a substantial grading of the compressive force of said keeper upon the conductor, a pivot pin engaging the sides of said channel shaped saddle at the middle thereof where said sides are offset outwardly, and a suspension member having legs engaging said pivot pin -within the pockets formed by said ofi'set sides and adjacent the flattened portions of said U-bolts.

5. A support for a conductor comprising an elongated saddle member curved downwardly at its ends and having a transversely curved seat for receiving a conductor, means for supporting said saddle member and a keeper for retaining the conductor in said seat, said keeper being shaped to follow the longitudinal contour of a conductor in said seat and having portions thereof which engage said conductor and graded in resiliency toward the ends thereof and terminating short of the portion of said conductor which is moved relative to said seat by vibrations of the conductor.

6. A support for a cable comprising an elongated saddle member curved downwardly at its ends and having a transversely curved seat for receiving a conductor, a pivotal support for said saddle member having the pivotal axis thereof approximate the point of intersection of lines drawn tangent to the conductor where it leaves the ends of said seat, a resilient keeper for retaining the conductor in said seat, the resiliency of the portions of said keeper which engage the conductor being graded to increase toward the ends thereof, said keeper terminating at points displaced inwardly from the portion of the conductor affected by vibrations, and clamping 'means having contact near the mid portion of said keeper piece, the area of contact being extended longitudinally of said conductor to distribute the clamping pressure on said conductor longitudinally thereof.

JOHN J. TAYLOR. 

